How long will prairie and savanna forbs last in southern Wisconsin in the absence of restoration or weed control?

There is very little “on-the-ground” data on the character of southern Wisconsin prairies and oak savanna before restoration work began. By chance I discovered an early detailed report of the spring flora for 1936 for an area that is contiguous with Pleasant Valley Conservancy (PVC). This report (found in the UW-Madison Herbarium documents archive) was prepared by a group of students taking Norman Fassett’s Spring Flora of Wisconsin course. The lead author was Edith Seymour Jones, who was a plant pathologist and experienced plant taxonomist. The location of this study was the Sevenson farm in Section 8 of the Town of Vermont. PVC is in the adjacent Section 5. Our bluffs and the bluffs surveyed are identical in geology, soils, and aspect. (The photo below from 1936 shows PVC as the hill in the left in the distance. The road in the foreground is County Highway F.)

Pleasant Valley Conservancy is the hill seen in the distance

Considering that this is just a “spring flora”, done around the middle of May, the species diversity is quite high.

The species list has over 50 species, of which the ones shown in the accompanying table are the most noteworthy. As the table shows, most of these species have also appeared at PVC after restoration, and many of them were in the species list before any restoration work had started. As far as it is known, these species first arose in PVC without the agency of external seeding.

It is encouraging to learn that so many prairie and savanna species survived from 1936 until 1998 (32 years) when restoration work at PVC began in earnest.

Check list for 1936 flora in Section 8; Town of Vermont
Latin name	Common name	Also present in 1998 PVC list
Achillea millefolium	Yarrow	x
Anemone cylindrica	Prairie thimbleweed	x
Anemone patens	Pasque flower	x
Anemone quinquefolia	Wood anemone	x
Antennaria neglecta	Field pussytoes	x
Aquilegia canadensis	Wild columbine	x
Arabis lyrata	Sand cress	x
Aralia nudicaulis	Wild sarsaparilla	x
Arenaria stricta	Sandwort	x
Campanula rotundifolia	Harebell	x
Ceanothus americanus	New Jersey tea	x
Celastrus scandens	Climbing bittersweet	x
Comandra  umbellata	False toadflax
Cypripedium calceolus pubescens	Large yellow lady-slipper	x
Dicentra cucullaria	Dutchman's breeches	x
Dodecatheon meadia	Shooting star	x
Erigeron philadelphicus	Marsh fleabane	x
Fragaria virginiana	Wild strawberry	x
Galium aparine	Catchweed	x
Geranium maculatum	Wild geranium	x
Heuchera richardsonii	Prairie alum-root	x
Hypoxis hirsuta	Yellow star-grass	x
Iris virginica shrevei	Wild iris	x
Lathyrus venosus	Forest pea	x
Lithospermum canescens	Hoary puccoon	x
Orchis spectabolis	Showy orchis	x
Osmorhiza claytoni	Hairy sweet cicely	x
Oxalis violacea	Violet wood-sorrel	x
Pedicularis canadensis	Wood betony	x
Phlox pilosa	Prairie phlox
Podophyllum peltatum	May-apple	x
Polemonium reptans	Jacob's ladder	x
Polygala senega	Seneca snakeroot	x
Potentilla canadesis	Dwarf cinquefoil
Ranunculus abortivus	Small-flowered buttercup	x
Ranunculus fascicularis	Early buttercup	x
Rosa sp.	Rose	x
Scutellaria parvula	Small skullcap	x
Senecio pauperculus	Balsam ragwort	x
Senecio plattensis	Prairie ragwort	x
Silene antirrhina	Sleepy catchfly	x
Sisyrinchium campestre	Blue-eyed grass	x
Smilacina racemosa	False Solomon's seal	x
Smilacina stellata	Starry false Solomon's seal	x
Stellaria longifolia	Stitchwort	x
Taenidia integerrima	Yellow pimpernel	x
Triosteum perfoliatum	Tinker's weed	x
Uvularia grandiflora	Bellwort	x
Viola pedatifida	Prairie violet	x
Viola soraria	Door-yard violet	x
Zizia aurea	Golden Alexanders	x